Camera system

Abstract

The present invention provides, on the camera body side thereof, a pulse signal generator for generating continuous pulse signal trains, the frequency of which is four times the frequency employed for driving a supersonic motor and a pulse width which corresponds to the pulse width of an AC voltage for driving the supersonic motor. Furthermore, a unit detachable from the camera body and including the supersonic motor generates the AC voltage for driving the supersonic motor which corresponds to the pulse signal.

What is claimed is: 
     
       1. A camera system composed of a unit and a camera body from which said unit is detachable, said unit including a supersonic motor having a predetermined operating frequency and arranged to be detachable from said camera body, said camera system comprising: pulse signal generating means provided in said camera body and generating a pulse signal having a frequency which is four times the operating frequency for driving said supersonic motor and a pulse width which corresponds to a pulse width of an AC voltage for driving said supersonic motor;   AC voltage generating means provided in said unit and generating said AC voltage to be applied to said supersonic motor responsive to said pulse signal derived from said pulse signal generating means;   first information transmitting means provided in said unit and performing information communication to and from said camera body;   driving parameter changing instruction means provided in said unit, for detecting rotation of said supersonic motor and determining information about a change in at least one driving parameter including a frequency and a pulse width of said AC voltage;   second information transmitting means provided in said camera body and performing information communication to and from said unit;   pulse signal control means provided in said camera body and controlling at least one of said frequency and said pulse width of said pulse signal in accordance with said information about a change in said driving parameter determined by said driving parameter changing instruction means; and   transmitting means provided in said camera body for transmitting said pulse signal to said unit over a single pulse line.   
     
     
       2. A camera system composed of a unit and a camera body from which said unit is detachable and said unit including a supersonic motor having a predetermined operating frequency and arranged to be detachable from said camera body, said camera system comprising: pulse signal generating means provided in said camera body and generating a pulse signal having a frequency which is four times the predetermined operating frequency for driving said supersonic motor and a pulse width which corresponds to a pulse width of an AC voltage for driving said supersonic motor;   pulse signal forming means provided in said unit and forming four pulses composed of first to fourth pulse signals from said pulse signal;   said pulse signal being coupled to said pulse signal forming means through a single pair of contacts respectively provided on said camera body and said unit, said pair of contacts being engaged when said unit is mounted on said camera body;   sequence changing means provided in said unit for respectively changing the sequence of said first to fourth pulse signals in accordance with an instruction to rotate said supersonic motor in a forward direction or an instruction to rotate said supersonic motor in a reverse direction;   AC voltage generating means provided in said unit for generating said AC voltage to be applied to said supersonic motor in accordance with said first to fourth pulse signals; and   driving parameter changing instruction means provided in said unit, for detecting rotation of said supersonic motor and determining information about a change in at least one driving parameter including a frequency and a pulse width of said AC voltage.   
     
     
       3. A method for controlling operation of a supersonic motor in a unit of a camera system composed of a camera body from which said unit is detachable and said unit including a supersonic motor having an operating frequency and arranged to be detachable from said camera body, said method comprising the steps of: (a) transmitting parameter information items, which include an initial frequency and a pulse width of operating signals for operating said supersonic motor, from said unit to said camera body by a communication link;   (b) generating a pulse signal in the camera body in accordance with said parameter information and transmitting said pulse signal to said unit over a single line;   (c) driving an AC voltage generating circuit in said unit for generating driving AC voltage responsive to said pulse signal delivered to the unit to commence driving of said supersonic motor;   (d) monitoring rotation of said supersonic motor, to determine information about change in a value of at least one parameter which includes a frequency and a pulse width of the supersonic motor in accordance with the result of monitoring and issuing an instruction of change to said camera body by communication thereto;   (e) changing one of said frequency and said pulse width of said pulse signal in said camera body responsive to said instruction of said change issued from said unit during step (d); and   (f) repeating steps (b) to (e) until a predetermined quantity of driving is established and stopping said unit by halting said driving AC voltage generating circuit when said predetermined quantity of driving is established to stop driving of said supersonic motor.   
     
     
       4. A method of controlling operation of a supersonic motor in a unit of a camera system composed of said unit and a camera body from which said unit is detachable and which includes a pulse signal generating means and said unit including a supersonic motor arranged to be detachable from said body and including driving AC voltage generating means, said method comprising the steps of: (a) generating in said camera body a pulse signal and transmitting said pulse signal to said unit over a single line;   (b) causing said AC voltage generating means to generate driving AC voltage in accordance with the pulse signal received in said unit;   (c) monitoring rotation of said supersonic motor in said unit and transmitting the result of monitoring to said camera body;   (d) changing at least one of a frequency and a pulse width of said pulse signal in accordance with information representing said result of monitoring received in said camera body; and   (e) repeating steps (a) to (d).   
     
     
       5. A camera system comprising a camera body and a unit to be detachably coupled to said camera body; said camera body including:   first interface means for transmitting/receiving data to and from said unit;   pulse generating means for generating a single pulse train having a predetermined frequency and a predetermined duty ratio in accordance with certain data received by said first interface means;   first connection means which includes a single contact terminal connected to said pulse generating means for transmitting said pulse train outside of said camera body; and   second connection means connected to said first interface means to receive said data; and   said unit including:   third connection means including a single contact terminal being connected to said first connection means when said unit is coupled to said camera body;   fourth connection means being connected to said second connection means when said unit is coupled to said camera body;   AC voltage generating means for generating a plurality of AC voltage signals having different phases in accordance with said pulse train supplied from said third connection means;   a supersonic motor which is operated responsive to said AC voltage supplied from said AC voltage generating means;   monitor means for detecting a state of operation of said supersonic motor including means to transmit the result of the detection; and   second interface means for transmitting data about the result of the detection supplied from said monitor means to said camera body via said fourth connection means.   
     
     
       6. A camera system according to claim 5, wherein said pulse generating means changes at least one characteristic of said pulse train including a frequency and a duty cycle of said pulse train in accordance with data about said result of the detection developed by said monitor means and received by said first interface means. 
     
     
       7. A camera system comprising: a camera body;   an auxiliary unit arranged to be detachable from said camera body;   a supersonic motor provided in said auxiliary unit;   AC voltage generating means provided in said auxiliary unit to generate an AC voltage having an operating frequency for driving said supersonic motor;   instruction means provided in said auxiliary unit to detect a state of operation of said supersonic motor and transmit a command to change one of a group of parameters including a frequency and a pulse width of said AC voltage;   pulse signal generating means provided in said camera body to time-sequentially generate a pulse signal train having a period which is four times the operating frequency of said AC voltage and having a predetermined pulse width;   control means provided in said camera body to change at least one of said frequency and said pulse width of said pulse signal train responsive to the output from said instruction means;   transmitting means provided between said camera body and said auxiliary unit, including a single contact on said camera body and another single contact on said auxiliary unit, said contacts engaging one another when said unit is mounted upon the camera body to transmit said pulse signal train to said AC voltage generating means; and   communication means for transmitting said output from said instruction means to said control means.   
     
     
       8. A camera system according to claim 7, wherein said control means includes means for successively increasing or decreasing the total sum of the pulse periods of two adjacent pulses of a group of four continuous pulses of said pulse signal train responsive to the output from said instruction means. 
     
     
       9. A camera system according to claim 7, wherein said AC voltage generating means includes conversion means for converting a series of four pulses of said pulse signal train into four types of independent pulses for forming said AC voltage. 
     
     
       10. A camera system comprising a camera body, an auxiliary unit including a supersonic motor and arranged to be detachably mounted to said camera body and connection means located on a detachment surface between said camera body and said auxiliary unit to transmit/receive signals between said camera body and said auxiliary unit, said auxiliary unit having: AC means for generating an AC voltage for driving said supersonic motor; and   instruction means for detecting a state of operation of said supersonic motor to transmit a command of changing a frequency of said AC voltage, and said camera body having:   pulse means for generating a single pulse signal train having a predetermined frequency and a pulse width for generating said AC voltage;   means for controlling said frequency of said pulse signal in accordance with information supplied from said instruction means; and   means for coupling said pulse means to said AC means including a single contact on the camera body coupled to said pulse means and another single contact on the auxiliary unit coupled to AC means, said contacts being engaged when the auxiliary unit is mounted on the camera body.   
     
     
       11. A camera system comprising: a camera body;   an auxiliary unit arranged to be detachably mounted to said camera body and including a supersonic motor;   pulse signal generating means provided for said camera body to generate a series of pulses in a pulse signal train, said pulses having a predetermined pulse width and a frequency;   AC means provided in said auxiliary unit to generate an AC voltage for driving said supersonic motor in accordance with said pulse signal train, said pulse signal train being coupled to the AC means by a single line;   a member to be driven which is provided in said auxiliary unit and which is driven by said supersonic motor;   means provided in said auxiliary unit to monitor a state of operation of said supersonic motor;   means provided in said auxiliary unit to detect an operational velocity of said member to be driven; and   means provided in said camera body for changing frequency of a pulse supplied from said pulse signal generating means to adjust an AC voltage to be applied to said supersonic motor at an optimum frequency responsive to an output from said monitor means, and changing a width of said pulse supplied from said pulse signal generating means to adjust operational velocity of said supersonic motor responsive to an output from said detection means.   
     
     
       12. A camera system having a unit and a camera body to which said unit is detachably mounted, said unit including a supersonic motor having monitor means for detecting rotation, said camera system comprising: (a) storage means provided in said unit to store at least two types of data relating to a phase comparison timing of an output signal from said monitor means;   (b) pulse signal generating means provided in said camera body to generate a pulse having a frequency which is about four times a frequency for driving said supersonic motor and a pulse width which corresponds to data relating to a phase comparison timing of an output signal from said monitor means;   (c) pulse forming means provided in said unit to form four pulses from said pulse signal as first to fourth pulse signals;   (d) AC voltage generating means provided in said unit to generate an AC voltage to be applied to said supersonic motor responsive to said first to fourth pulse signals;   (e) phase discriminating means provided in said unit to discriminate a phase of an output signal from monitor means in accordance with data stored in said storage means relating to said phase comparison timing and said pulse signal; and   (f) driving parameter changing instruction means provided in said unit to determine information about a change in frequency of said pulse signal responsive to an output from said phase discriminating means.   
     
     
       13. A camera system comprising: a camera body;   an auxiliary unit arranged to be detachably mounted to said camera body and including a supersonic motor;   pulse signal generating means provided in said camera body to generate a series of pulses in a pulse signal train having a predetermined pulse width and frequency;   means provided in said auxiliary unit to generate an AC voltage for driving said supersonic motor in accordance with said pulse signal train;   storage means provided in said auxiliary unit to store predetermined timing data;   means provided in said auxiliary unit to discriminate a state of a phase of an output from a means which monitors operation of said supersonic motor;   timing setting means provided in said camera body to set discrimination timing of said discriminating means as a pulse width of said pulse signal in accordance with the output from the storage means in said auxiliary unit; and   means provided in said camera body to change frequency of a pulse supplied from said pulse signal generating means to set said AC voltage at an optimum frequency responsive to an output from said discriminating means.   
     
     
       14. A camera system having, as a driving source, a supersonic motor which is driven by an AC voltage and which has a monitor electrode for detecting an operating state of the motor, said camera system comprising: means for discriminating a phase of an output from said monitor electrode;   means for generating a basic pulse signal having a frequency of which is about four times that of a required AC voltage;   means for setting discriminating timing of said phase discriminating means in accordance with a pulse width of said basic pulse signal;   means for generating said AC voltage in accordance with a 4-phase driving pulse generated in accordance with said basic pulse signal; and   said discriminating timing setting means including means for setting said timing in accordance with the output from a storage means which stores first data about the sequential number of the pulse at which said discrimination is made assuming that continuous four basic pulses from one set and second data about the moment during the generation of said pulses at which said discrimination is made.   
     
     
       15. A camera system comprising a camera body and a unit to be detachably coupled to said camera body, said camera body including: first interface means for transmitting/receiving data to and from said unit;   pulse generating means for generating a pulse train having a predetermined frequency and a predetermined duty ratio responsive to said data received by said first interface means;   first connection means connected to said pulse generating means to transmit said pulse train outside of said camera body over a single line;   second connection means connected to said first interface means to receive said data; and   said unit including:   third connection means which is connected to said first connection means when said unit is coupled to said camera body;   fourth connection means which is connected to said second connection means when said unit is coupled to said camera body;   AC voltage generating means for generating a plurality of AC voltages having different phases in accordance with said pulse train supplied from said third connection means;   a supersonic motor which is operated responsive to said AC voltage supplied from said AC voltage generating means;   storage means for storing the operating characteristics of said supersonic motor; and   second interface means for transmitting data stored in said storage means to said camera body via said fourth connection means, wherein   said pulse generating means determines a duty ratio of said pulse train responsive to data supplied from said first interface means and stored in said storage means.   
     
     
       16. A camera system according to claims 15, wherein said unit further includes: monitor means for determining a state of the operation of said supersonic motor to transmit the result of the detection to said camera body via said second interface means, and   said pulse generating means including means for changing the frequency of said pulse train responsive to a result of a detection made by said monitor means supplied from said first interface means.   
     
     
       17. A camera system according to claim 16, wherein said monitor means monitors a state of the operation of said supersonic motor at a predetermined timing determined in accordance with said pulse train supplied from said second connection means. 
     
     
       18. A camera system comprising a camera body and a unit to be detachably coupled to said camera body, said camera body including:   pulse generating means for generating a single pulse train having a predetermined frequency and a predetermined duty ratio;   first connection means connected to said pulse generating means to transmit said pulse train outside of said camera body over a single line; and   said unit including:   second connection means connected to said first connection means when said unit is coupled to said camera body;   AC voltage generating means for generating a plurality of AC voltages having different phases responsive to said pulse train supplied from said second connection means; and   a supersonic motor which is operated responsive to said AC voltages supplied from said AC voltage generating means.   
     
     
       19. A camera system according to claim 18, wherein said unit further includes: monitor means for detecting a state of the operation of said supersonic motor; and   third connection means for transmitting an output from said monitor means to said camera body; and   said camera body further including:   fourth connection means connected to said third connection means when said unit is coupled to said camera body; wherein   said pulse generating means changes at least one of said frequency and said duty ratio of said pulse train in accordance with the output from said monitor means supplied from said fourth connection means.   
     
     
       20. A camera system according to claim 18, wherein said unit further includes: storage means for storing operating characteristics of said supersonic motor; and   third connection means for transmitting a value stored in said storage means to said camera body; and   said camera body further including:   fourth connection means connected to said third connection means when said unit is coupled said camera body, wherein   said pulse generating means determines said duty ratio of said pulse train in accordance with the output from said storage means supplied from said fourth connection means.   
     
     
       21. A camera system comprising a camera body and a unit detachably mounted to said camera body and including a supersonic motor, wherein said camera body includes pulse generating means for generating a signal pulse train for controlling a frequency for driving said supersonic motor and a driving velocity of said supersonic motor; and   said unit further includes AC voltage generating means for generating a plurality of AC voltages having different phases for driving said supersonic motor in accordance with said signal pulse train supplied from said camera body through a single line between said camera body and said detachable unit.   
     
     
       22. A camera system according to claim 21, wherein said unit further includes monitor means for detecting the state of the operation of said supersonic motor, and said pulse generating means of said camera body includes means for changing at least one of said frequency and said duty ratio of said pulse train in accordance with an output from said monitor means. 
     
     
       23. A camera system according to claim 21, wherein said unit further includes: storage means for storing the characteristics of said supersonic motor; and   said pulse generating means of said camera body determines said duty ratio of said pulse train in accordance with the output from said storage means.